We have calculated and reviewed in a table form the average bulk M-shell fluorescence yield previously measured by different groups covering the period from 1955 to 2005. We have interpolated the weighted and unweighted mean values of the experimental data by using the analytical function ((omega) over bar (M)/(1-(omega) over bar (M)))(1/4) as a function of the atomic number (Z) to deduce the empirical average M-shell fluorescence yield in the atomic range of 70 <= Z <= 92. Also, we used the famous formula (omega) over bar (M) = A(Z-13)(4) to generalize the average M-shell fluorescence yield for elements with 19 <= Z <= 100. The results have been compared with other theoretical, experimental and empirical values reported in the literature and a reasonable agreement has been obtained. (C) 2014 Elsevier Ltd. All rights reserved.